The influence of nitrification inhibitor (nitrapyrin), fertilizer nitrogen application rate, and nitrogen splitting were evaluated in a lysimeter experiment with wheat grown in a sandy loam (Torrifluvent) highly calcareous soil [292 g Kg' CaCO3]. The effect of treatments on wheat yield. N uptake and N recovery was reported. Wheat yields were most significantly affected by the rate of applied N Increasing fertilizer application rate from 50 to 150,250. and 350 kg N ha-1 mulled in 88, 139 and 166% ma eases in grain yield (G,Y) respectively. Neither nitrapyrin addition nor nitrogen splitting resulted in any significant increases in wheal yield. However, number of tillers (NT) was significantly increased b> addition of nitrapyrin. The nitrification inhibitor, therefore, did apparently conserve fertilizer N. but not enough to affect grain yield. Nitrapyrin did not result in any increases of N concentration in plants, whereas increas¬ing the splitting of N to nine splits, resulted in a significant increase in N concentration in wheat grains leaching losses of N were generally very email and constitute an insignificant path was for N losses [0.6- 2.8].